Signaling system



1,521,01&

Dec, 30,

H. 1.; GODFREY SIGNALING SYSTEM Filed June 5. 1920 Loose Coup/in WITNESSES: C2. 6M 62, He/M ATTORNEY Patented Dec. 30, 1924.

UNITED STATES HOWARD L. GODFREY, OF WILKINSB'U'RG,

PATENT OFFICE.

PENNSYLVANIA, ASSIGNOR TO WESTING- VANIA.

SIGNALING sYs'rnM."

Application filed June 3,

To all whom it may concern:

Be it known. that I, HOWARD L. GODFREY, a citizen of the United States, and a resident of Wilkinsburg, in the county of Al- 5 legheny and State of Pennsylvania, have invented a new and useful Improvement in Signaling Systems, of which the following is a specification.

This invention relates to wireless telegraphy and, .more especially, to signaling systems in which a variable reactance is employed for controlling the intensity of waves sent out by means of an antenna and it has, for one of its principal ebjects, the provision of a means whereby the intensity of the radiated energy may be modified Without affecting the wave length or the periodicity.

In the art of signaling, especially in connection with sustained waves, it has been usual to control the intensity of the emitted wave by short-circuiting a number of the spires forming the loading inductance.

This has manifest disadvantages in view of the fact that the periodicity is necessarily altered.

As a feature of my invention, therefore, I provide a frequency trap which; trap, when opened, enables the energy to be radiated from the system, whereas, when the said trap is closed, it offers a substantially infinite impedance to the antenna circuit.

A further feature of my invention is the provision of a multiple-contact system for opening and closing a condenser-containing circuit.

Other features and advantages of my system will also become apparent from an inspection of the drawings, when taken in conjunction with the accompanying description and will, moreover, be set forth in the claims. v

Fig. 1 is a diagrammatic view of a preferred form of my invention, as applied to a high-frequency generator; Fig. 2 isa diagram indicating an alternative form in which a loose inductive coupling is resorted to.

An antenna 1 is adjustably connected to a loa g c l 2 a one end, the oppo 1920. Serial No. 386,195.

end of which is connected to a coupling coil 2 grounded by means of an adjustable lead 4. In shunt to the loading coil 2 is a condenser 7 one terminal of which is con nected to a terminal 8 leading to one terminal of the loading coil 2, whereas the co operating parts of the condenser 9 are connected, through a multi-contact switch 10, to a lead 11 connected to a terminal 12-leading to the other terminal of the coupling coil.

It will be found that certain of the parts '9 of thecondenser are connected tofixed 1, the coupling between the grounded antenna and the driver circuit 5 6 is made as tight as possible. In this case, the condenser 7, with its contacting switch 10 and key 18 is connected across theloading coil 2 by means of the terminals 8 and 12, as indicated. In Fig. 2, however, loose coupling is employed, and vthe condenser, with its contact-controlling elements, (not shown) is connected across the loading coil 2, to-

gether With an adjustable amount of the spires of the coupling coil 2' by means of the terminals 8 and 12.

In operation, when the key 18 closes the circuit, the switch 10 causes the co-operating contacts 13 and 14: to engage and connect .the elements 9 of the condenser with the lead 11. Under these circumstances, a high-frequency generator 19, which is connected to the driver circuit 5', 6, is incapable of deliver ing much energy to the antenna 1, since,

with proper adjustment of inductance with capacitance in the circuit2, 12, 7 and 8, said c r ui be au edtQ-be resona t at h frequency of the generator 19, and practically no current will pass through such frequency trap. On the other hand, when the key 18 is released, enabling the contacts 14: to disengage themselves from the cooperating contacts 13, the condensance shunt to the inductance 2 is open-circuited, thereby enabling the high-frequency generator to deliver power to the antenna. Obviously, it is possible to so arrange matters that signal ing can take place when the key is pressed either down or up. This depends entirely upon how the armature 1-6 is actuated, relative to the electromagnet 15, in operating the contacting switch. In general, if desired, the opening andclosing of the switch 10 may bemade totake place in any suitable arc' preven'ting medium such as oil, well known to the art. The several contact mem bars 13 and 1 1 are separated practically s'imultaneous'ly'by' the action of the magnet 5, but it is not possible to make the separation absolutely synchronous. This is an ad'- vantage because the first pair to separate remove one condenser unit from the total capacity in parallel with the inductor 2. The change in the size of the capacity destroys the parallel-resonant nature of the circuit and there results a marked diminution in the current flowing through the condenser. Consequently, the pairs of contact members 13 and 14: which separate a few thousandths of a second later, are not carrying, at the moment of their separation, anywhere near as great a currentas before. The diminution in the current to be stopped at these contacts results in a great reduction in arcing.

Having disclosed certain embodiments of my invention, what I claim is:

1. In combination with a condenser having a plurality of plate members, a plurality of contact members for said plurality of plate members, and means for substantially simultaneously actuating said contact members.

2. In combination with an inductor, a condenser in parallel having a plurality of plate members, a plurality of contact members for said plurality of plate members, and a common actuating means for controlling said contact members together.

3. In combination with an alternatingcurrent circuit, a coil in series therewith, a plurality of condenser units in parallel with said coil, and simultaneously acting means for connecting said condenser units individually to said coil, and disconnecting the same individually therefrom. I

t. In combination. with an alternatingcurrent circuit, a coil in series therewith,- a plurality of condenser units in parallel with saidcoil', and means: for connecting said condenser" units individuallyand simultaneous- 1y to said coil and disconnecting the same individually and simultaneously tl'ierefrom.

5. In combination, a source of alternating current, a coil fed thereby, a, plurality of condenser units, means for connecting said condenser units in parallel with said coil, said condenser units and-coil when'thus connected being substantially anti-resonant to current of the frequency of said source, and means for disconnecting said condenser units from said coil, said means'acting upon all of said condenser units at one operation.

6. In combination, a source of alternating current, an inductor, a condenser comprising a number of units, one terminal of each unit being connected to the same end of said inductor, separable pairs of contact members, one pair for each unit, for connecting the otherterminals-o'f the units to the other end of the inductance, and a common actuating means for separating all of said pairs at one operation, the whole of said condenser constituting with said inductor a parallelresonant circuit at the frequency of said source, whereby the separation of any one of said pairs of contact members diminishes the current through the other pairs and arcing is minimized.

7. The combination with a plurality of condenser units, of a main terminal connected to one terminal of each of said condenser units, a second main terminal, switching means for connecting the remaining terminals of said condenser units and said second main terminal, a source of alternating-current potential connected across said main terminals, said source being correlated to the total capacity of all of said condensing units whereby the action of said switching means will be accompanied by a diminution in the potential across the condenser as the a several units are disconnected.

8. In a system of transmission of alternating-current power, the combination with a source of alternatingburrent energy, of a resonant circuit including an inductive reactance device and a plurality of condenser units, a main terminal connected to one terminal of each of said condenser units, a second main terminal, switching means for connecting the remaining terminals of said condenser units and said second main terminal, and means for substantially sim...ltaneously actuating said switching means.

9. The combination with asourc'e of alternating-current energy havinga predetermined frequency, of a transmitting circuit including a main reactan'ce device, and modulating means including an auxiliary reactance device having a reactive impedance which is substantially equal and opposite to the reactive impedance of said main reactance device at the frequency of said source, and means for, at will, either connecting said auxiliary reactance device inshunt'circuit with said main reactance device or substantially open-circuiting said shunt circuit contalnlng sald auxiliary reactance device.

10. The comblnatlon with a source of alternating-current energy having predetermined frequency, of a tuned transmitting circuit including a main reactance device, and modulating means including an auxiliary reactance device having a reactive impedance which is substantially equal and 0pposite to the reactive impedance of said main reactance device at the frequency of said source, and means for, at will, either connecting said auxiliary reactance device in shunt circuit with said main reactance device or substantially open-circuiting said 1 shunt circuit containing said auxiliary reactance devlce.

In testimony whereof I have hereunto subscribed my name this 27th day of May, 1920.

HOWARD L. GODFREY. 

